# Integrated Earthquake Catalog of the Eastern Sector of the Russian Arctic

^{1}

^{2}

^{3}

^{*}

## Abstract

**:**

## 1. Introduction

- The sequential merging of three regional catalogs of the GS RAS and the ISC catalog, which implies the identification of duplicate events in the border areas of responsibility of the different networks; and
- The unification of magnitude estimates in the integrated catalog by constructing regression relationships for the different types of magnitude/energy class due to the exact association of data from the different catalogs related to the same event.

## 2. Materials and Methods

- The regional catalog of Yakutia from the annual journals Earthquakes in the USSR (1962–1991), Earthquakes in Northern Eurasia (1992–2014), and Earthquakes in Russia (2015–2019) (GS RAS) (hereinafter YAK);
- The regional catalog of the northeast of Russia from the annual journals Earthquakes in the USSR (1968–1991), Earthquakes in Northern Eurasia (1992–2014), and Earthquakes of Russia (2015–2019) (GS RAS) (hereinafter NER);
- The regional catalog of earthquakes in Kamchatka of the Kamchatka Branch of the GS RAS, 1962–2019 (hereinafter KAM); and
- The ISC 1962–2020 catalog, which is a composite catalog containing data from many world and Russian agencies.

- Earthquakes from the ISC global catalog (the abbreviation of the ISC and GCMT agency in Table 2) with the magnitudes M
_{W}^{GCMT}and/or mb^{ISC}are the core (hereinafter CORE) (1393 events); - Earthquakes from Russian catalogs with local estimates for the magnitude of weak events. In the intersection zones, preference is given to the data from the catalog of Yakutia (Table 1);
- Other earthquakes from the ISC (abbreviation of the ISC agency in Table 2, without the magnitude data M
_{W}^{GCMT}or mb^{ISC}), as well as data from other agencies in the ISC catalog (16,642 events). This selection from the ISC catalog will be further denoted by ISC_Other.

## 3. Results

#### 3.1. Merging Catalogs

#### 3.1.1. Stage 1. Merging YAK and NER

#### 3.1.2. Stage 2. Merging YAK_NER and KAM into the RUS Catalog

#### 3.1.3. Stage 3. Merging RUS and Data from the ISC_Other Catalog

#### 3.1.4. Stage 4. Merging RUS_ISC and CORE

_{W}

^{GCMT}or mb

^{ISC}. As an additional catalog, we consider RUS_ISC, obtained at the previous stage. The preliminary analysis of the duplicates was performed with the standard catalog distribution parameters ${\sigma}_{T}=0.05$ min, ${\sigma}_{X}=15$ km, and ${\sigma}_{Y}=15$ km. Approximately 1000 duplicates were identified and used to determine the variances. It was verified that each of the parameters follows a normal distribution and that the mean is small compared to the standard deviation for all three parameters (DT, DX, and DY). It was also verified that the variance is almost independent of the event magnitude and time (Figure 10).

#### 3.1.5. Stage 5. Exclusion of Explosions

#### 3.2. Magnitudes in the Integrated Catalog of the Eastern Sector of the Russian Arctic

_{W}, which is preferable when analyzing estimates of different magnitude scales [37,38]. However, when moving from large to small magnitudes (from global estimates to regional ones), discrepancies in M

_{W}estimates are observed everywhere at M < 5.0 [39,40]. It should be noted that the Eastern Arctic region was not considered in [39].

_{W}

^{GCMT}magnitude. If the global estimate of moment magnitude is unknown, we prefer the magnitude mb

^{ISC}, which is used by ISC in its practice to obtain “quasi-M

_{W}” estimates in the range M < 5.0 [41].

_{R}”, “K

_{F}”, or “K

_{S}” for Rautian, Fedotov, or Solov`ev, respectively, or “K

_{P}”, “K

_{S}”, or “K

_{PS}” for the wave type, which were used for calculation. In this paper, we stand for the second approach to emphasize the difference in energy class scales. Therefore, the estimates expressed in energy classes were converted to M

_{W}using regression relations. In the studied territory, the number of earthquakes with the known magnitude M

_{W}

^{GCMT}is small, so regressions with the magnitude mb

^{ISC}are built, which is well aligned with M

_{W}

^{GCMT}[41].

^{ISC}. In few cases, when there were no pairs to determine direct correlations to mb

^{ISC}, we used indirect correlations with other magnitudes, and we consider these correlations unreliable (indicated in the “Note” column of Table 4). The 95% confidence intervals are constructed by the Grapher Golden Software built-in tool (https://www.goldensoftware.com/products/grapher, (accessed on 20 March 2022)).

- M
_{W}^{GCMT}or M_{S}^{ISC}for strong earthquakes before 1976; - mb
^{ISC}; - Magnitude by energy class; and
- Other magnitudes.

_{W}

^{GCMT}and mb

^{ISC}magnitudes in the studied territory (mb = 0.99M

_{W}+ 0.03). Earthquakes with an M

_{W}of <6.0 were used to construct the best linear approximation. For stronger earthquakes, the magnitude mb saturates and becomes smaller than M

_{W}. The magnitude M

_{S}≈ M

_{W}is used for earthquakes with an M

_{W}of ≥6.0. For weaker earthquakes, M

_{S}< M

_{W}(Figure 13b) is used, which generally agrees with previously obtained correlations [41].

_{W}

^{GCMT}. During the considered period, 15 earthquakes with an M of >6.0 occurred. Two strong earthquakes occurred in 1969 (mb = 6.4 and M

_{S}= 7.5) and 1971 (mb = 6.0 and M

_{S}= 7.0). For these earthquakes, the M

_{S}estimate is preferred (Figure 13b, Table 5). For the remaining 13 strong earthquakes, the magnitude M

_{W}

^{GCMT}is known.

^{ISC}was used (Figure 14). The Yakutsk and Northeastern branches of the GS RAS estimate the Rautian K

_{PS}class [42], while the Kamchatka Branch estimates the Fedotov K

_{S}class [44]. Earthquakes in Kamchatka were selected only in the studied territory, north of latitude 57.5°.

^{ISC}and K

_{PS}is the same in Yakutia and in the northeast. The ratio for K

_{S}in Kamchatka is noticeably different since in the formula of energy classes according to Fedotov [43,44], K

_{S}= 2lgA

_{peak}+ f(r), while in the classes according to Rautian [42,43], K

_{PS}= 1.8lgA

_{peak}+ f(r), where A

_{peak}is a peak amplitude of an S-wave or the sum of peak amplitudes of P- and S-waves, and f(r) is an attenuation function.

_{W}, which is an absolute scale in the first approximation. Therefore, a shift-type transformation M = M + constant was used, corresponding to the approach of [45], which assumed that one day, relative logarithmic magnitude estimates would be converted to absolute energy estimates by adding a constant (“Since the scale is logarithmic, any future reduction to an absolute scale can be accomplished by adding a constant to the scale numbers”). Taking into account that such ratios were obtained for limited ranges of magnitudes, and, in particular, magnitude ranges within M < 5, we consider that the assumption of the absence of nonlinear effects can be applied.

_{W}

^{GCMT}is small; therefore, to construct correlations, we used all earthquakes from the ISC catalog for which the magnitude mb

^{ISC}and the studied magnitude are known. Reliable correlations with mb

^{ISC}are determined for 617 earthquakes. For 609 events, unreliable correlations are determined. This is due either to a small number of events or to the use of an indirect correlation with other magnitudes.

## 4. Conclusions

_{W}magnitude is calculated by converting the energy class using the original regression relationships (Table 4). The distribution of event magnitudes over time and magnitude–frequency graphs are shown in Figure 20. The integrated catalog completeness is quite heterogeneous. A detailed analysis of the changes in the level of registration in space and time is a big work that goes beyond the scope of the present study. We plan to conduct this work in the future.

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

- Imaeva, L.P.; Imaev, V.S.; Koz’min, B.M. Dynamics of the Zones of Strong Earthquake Epicenters in the Arctic–Asian Seismic Belt. Geosciences
**2019**, 9, 168. [Google Scholar] [CrossRef] [Green Version] - Daragan-Sushchova, L.A.; Petrov, O.V.; Sobolev, N.N.; Daragan-Sushchov, Y.I.; Grin’ko, L.R.; Petrovskaya, N.A. Geology and tectonics of the northeast Russian Arctic region, based on seismic data. Geotectonics
**2015**, 49, 469–484. [Google Scholar] [CrossRef] - Kanao, M.; Suvorov, V.; Toda, S.; Tsuboi, S. Seismicity, structure and tectonics in the Arctic region. Geosci. Front.
**2015**, 6, 665–677. [Google Scholar] [CrossRef] [Green Version] - Skorkina, A.A. Scaling of two corner frequencies of source spectra for earthquakes of the Bering fault. Russ. J. Earth Sci.
**2020**, 20, ES2001. [Google Scholar] [CrossRef] - Imaev, V.S.; Imaeva, L.P.; Koz’min, B.M. Strong Ulakhan-Chistay earthquake (Ms = 5.7) January 20, 2013 in the zone of influence Ulakhan fault system in North East Russia. Vestn. St. Petersburg Univer. Earth Sci.
**2020**, 65, 740–759. (In Russian) [Google Scholar] [CrossRef] - Shibaev, S.V.; Kozmin, B.M.; Imaev, V.S.; Imaeva, L.P.; Petrov, A.F.; Starkova, N.N. The February 14, 2013 Ilin-Tas (Abyi) earthquake (Mw = 6.7), Northeast Yakutia. Russ. J. Seismol.
**2020**, 2, 92–102. [Google Scholar] [CrossRef] - Chebrov, V.N. The Olyutorskii earthquake of April 20, 2006: Organizing surveys, observations, problems, and results. J. Volcanol. Seismol.
**2010**, 4, 75–78. [Google Scholar] [CrossRef] - Rogozhin, E.A.; Ovsyuchenko, A.N.; Marakhanov, A.V.; Novikov, S.S. A geological study of the epicentral area of the April 20(21), 2006 Olyutorskii earthquake. J. Volcanol. Seismol.
**2010**, 4, 79–86. [Google Scholar] [CrossRef] - Lander, A.V.; Levina, V.I.; Ivanova, E.I. The earthquake history of the Koryak Upland and the aftershock process of the M
_{W}7.6 April 20(21), 2006 Olyutorskii earthquake. J. Volcanol. Seismol.**2010**, 4, 87–100. [Google Scholar] [CrossRef] - Dzeboev, B.A.; Agayan, S.M.; Zharkikh, Y.I.; Krasnoperov, R.I.; Barykina, Y.V. Strongest Earthquake-Prone Areas in Kamchatka. Izv. Phys. Solid Earth
**2018**, 54, 284–291. [Google Scholar] [CrossRef] - Dzeboev, B.A.; Gvishiani, A.D.; Belov, I.O.; Agayan, S.M.; Tatarinov, V.N.; Barykina, Y.V. Strong Earthquake-Prone Areas Recognition Based on an Algorithm with a Single Pure Training Class: I. Altai-Sayan-Baikal Region, M ≥ 6.0. Izv. Phys. Solid Earth
**2019**, 55, 563–575. [Google Scholar] [CrossRef] - Dzeboev, B.A.; Karapetyan, J.K.; Aronov, G.A.; Dzeranov, B.V.; Kudin, D.V.; Karapetyan, R.K.; Vavilin, E.V. FCAZ-recognition based on declustered earthquake catalogs. Russ. J. Earth Sci.
**2020**, 20, ES6010. [Google Scholar] [CrossRef] - Gorshkov, A.I.; Soloviev, A.A. Recognition of earthquake-prone areas in the Altai-Sayan-Baikal region based on the morphostructural zoning. Russ. J. Earth Sci.
**2021**, 21, ES1005. [Google Scholar] [CrossRef] - Gvishiani, A.; Dobrovolsky, M.; Agayan, S.; Dzeboev, B. Fuzzy-based clustering of epicenters and strong earthquake-prone areas. Environ. Eng. Manag. J.
**2013**, 12, 1–10. [Google Scholar] - Gvishiani, A.D.; Dzeboev, B.A.; Agayan, S.M. FCAZm intelligent recognition system for locating areas prone to strong earthquakes in the Andean and Caucasian Mountain belts. Izv. Phys. Solid Earth
**2016**, 52, 461–491. [Google Scholar] [CrossRef] - Gvishiani, A.D.; Dzeboev, B.A.; Sergeyeva, N.A.; Belov, I.O.; Rybkina, A.I. Significant Earthquake-Prone Areas in the Altai–Sayan Region. Izv. Phys. Solid Earth
**2018**, 54, 406–414. [Google Scholar] [CrossRef] - Gvishiani, A.D.; Soloviev, A.A.; Dzeboev, B.A. Problem of Recognition of Strong-Earthquake-Prone Areas: A State-of-the-Art Review. Izv. Phys. Solid Earth
**2020**, 56, 1–23. [Google Scholar] [CrossRef] - Levin, B.W.; Kim, C.U.; Solovjev, V.N. A seismic hazard assessment and the results of detailed seismic zoning for urban territories of Sakhalin Island. Russ. J. Pac. Geol.
**2013**, 7, 455–464. [Google Scholar] [CrossRef] - Lunina, O.V.; Gladkov, A.S.; Gladkov, A.A. Systematization of active faults for the assessment of the seismic hazard. Russ. J. Pac. Geol.
**2012**, 6, 42–51. [Google Scholar] [CrossRef] - Magrin, A.; Peresan, A.; Kronrod, T.; Vaccari, F.; Panza, G.F. Neo-deterministic seismic hazard assessment and earthquake occurrence rate. Eng. Geol.
**2017**, 229, 95–109. [Google Scholar] [CrossRef] - Nekrasova, A.; Kossobokov, V.G.; Parvez, I.A.; Tao, X. Seismic hazard and risk assessment based on the unified scaling law for earthquakes. Acta Geod. Et Geophys.
**2015**, 50, 21–37. [Google Scholar] [CrossRef] [Green Version] - Ulomov, V.I. Seismic hazard of Northern Eurasia. Ann. Di Geofis.
**1999**, 42, 1023–1038. [Google Scholar] [CrossRef] - Zaalishvili, V.; Chernov, Y.K. Methodology of detailed assessment of the seismic hazard of the Republic of North Ossetia-Alania. Open Constr. Build. Technol. J.
**2018**, 12, 309–318. [Google Scholar] [CrossRef] - Zaalishvili, V.B.; Rogozhin, E.A. Assessment of seismic hazard of territory on basis of modern methods of detailed zoning and seismic microzonation. Open Constr. Build. Technol. J.
**2011**, 5, 30–40. [Google Scholar] [CrossRef] [Green Version] - Zavyalov, A.D.; Peretokin, S.A.; Danilova, T.I.; Medvedeva, N.S.; Akatova, K.N. General Seismic Zoning: From Maps GSZ-97 to GSZ-2016 and New-Generation Maps in the Parameters of Physical Characteristics. Seism. Instr.
**2019**, 55, 445–463. [Google Scholar] [CrossRef] - Beauval, C.; Yepes, H.; Palacios, P.; Segovia, M.; Alvarado, A.; Font, Y.; Aguilar, J.; Troncoso, L.; Vaca, S. An Earthquake Catalog for Seismic Hazard Assessment in Ecuador. Bull. Seismol. Soc. Am.
**2013**, 103, 773–786. [Google Scholar] [CrossRef] - Kondorskaya, N.V.; Shebalin, N.V. (Eds.) New Catalog of Strong Earthquakes in the USSR from Ancient Times through 1977; Report SE-31; World Data Center A for Solid Earth Geophysics: Boulder, CO, USA, 1982; 608p. [Google Scholar]
- Shebalin, P.N. Compilation of earthquake catalogs as a task of clustering analysis with learning. Dokl. Akad. Nauk. SSSR
**1987**, 292, 1083–1086. [Google Scholar] - Markušić, S.; Gülerce, Z.; Kuka, N.; Duni, L.; Ivančić, I.; Radovanović, S.; Glavatović, B.; Milutinović, Z.; Akkar, S.; Kovačević, S.; et al. An updated and unified earthquake catalogue for the Western Balkan Region. Bull. Earthq. Eng.
**2016**, 14, 321–343. [Google Scholar] [CrossRef] - Sawires, R.; Santoyo, M.A.; Peláez, J.A.; Corona Fernández, R.D. An updated and unified earthquake catalog from 1787 to 2018 for seismic hazard assessment studies in Mexico. Sci. Data
**2019**, 6, 241. [Google Scholar] [CrossRef] [Green Version] - Braclawska, A.; Idziak, A. Unification of data from various seismic catalogues to study seismic activity in the Carpathians Mountain arc. Open Geosci.
**2019**, 11, 837–842. [Google Scholar] [CrossRef] - Long, F.; Jiang, C.; Qi, Y.; Liu, Z.; Fu, Y. A joint probabilistic approach for merging earthquake catalogs of two neighboring seismic networks: An example of the 2014 Ludian sequence catalog. Acta Geophys. Sin.
**2018**, 61, 2815–2827. [Google Scholar] [CrossRef] - Muller, S.; Garda, P.; Muller, J.-D.; Cansi, Y. Seismic events discrimination by neuro-fuzzy merging of signal and catalogue features. Phys. Chem. Earth Part. A Solid Earth Geod.
**1999**, 24, 201–206. [Google Scholar] [CrossRef] - Vorobieva, I.; Gvishiani, A.; Dzeboev, B.; Dzeranov, B.; Barykina, Y.; Antipova, A. Nearest Neighbor Method for Discriminating Aftershocks and Duplicates When Merging Earthquake Catalogs. Front. Earth Sci. SI Nat. Clust. Earthq. Process. Var. Scales Lab. Exp. Large Earthq.
**2022**, 10, 820277. [Google Scholar] [CrossRef] - Zaliapin, I.; Ben-Zion, Y. Earthquake clusters in southern California. I: Identification and stability. J. Geophys. Res. Solid Earth
**2013**, 118, 2847–2864. [Google Scholar] [CrossRef] - Zaliapin, I.; Ben-Zion, Y. A global classification and characterization of earthquake clusters. Geophys. J. Int.
**2016**, 207, 608–634. [Google Scholar] [CrossRef] [Green Version] - Kanamori, H. The Energy Release in Great Earthquakes. J. Geophys. Res.
**1977**, 82, 2981–2987. [Google Scholar] [CrossRef] [Green Version] - Hanks, T.C.; Kanamori, H. A Moment Magnitude Scale. J. Geophys. Res. Solid Earth
**1979**, 84, 2348–2350. [Google Scholar] [CrossRef] - Di Giacomo, D.; Harris, J.; Storchak, D.A. Complementing regional moment magnitudes to GCMT: A perspective from the rebuilt International Seismological Centre Bulletin. Earth Syst. Sci. Data
**2021**, 13, 1957–1985. [Google Scholar] [CrossRef] - Abubakirov, I.R.; Gusev, A.A.; Guseva, E.M.; Pavlov, V.M.; Skorkina, A.A. Mass determination of moment magnitudes Mw and establishing the relationship between Mw and ML for moderate and small Kamchatka earthquakes. Izv. Phys. Solid Earth
**2018**, 54, 33–47. [Google Scholar] [CrossRef] - Di Giacomo, D.; Bondár, I.; Storchak, D.A.; Engdahl, E.R.; Bormann, P.; Harris, J. ISC-GEM: Global Instrumental Earthquake Catalogue (1900–2009), III. Re-computed MS and mb, proxy MW, final magnitude composition and completeness assessment. Phys. Earth Planet. Inter.
**2015**, 239, 33–47. [Google Scholar] [CrossRef] - Rautian, T.G. Energy of earthquakes. In Methods for the Detailed Study of Seismicity; The USSR Academy of Sciences: Moscow, Russia, 1960; pp. 75–114. (In Russian) [Google Scholar]
- Rautian, T.G.; Khalturin, V.I.; Fujita, K.; Mackey, K.G.; Kendall, A.D. Origins and methodology of the Russian energy K-class system and its relationship to magnitude scales. Seismol. Res. Lett.
**2007**, 78, 579–590. [Google Scholar] [CrossRef] - Fedotov, S.A. Energy Classification of the Kuril-Kamchatka Earthquakes and the Problem of Magnitudes; Nauka: Moscow, Russia, 1972; p. 117. (In Russian) [Google Scholar]
- Richter, C.F. An instrumental earthquake magnitude scale. Bull. Seismol. Soc. Am.
**1935**, 25, 1–32. [Google Scholar] [CrossRef]

**Figure 1.**Studied region. The circles are the earthquake epicenters from the YAK (black), NER (red), and KAM (blue) catalogs.

**Figure 3.**Distributions of DT, DX, and DY for the nearest events from the YAK and NER catalogs, and the dependence of the standard deviations ${\sigma}_{T}$, ${\sigma}_{X}$, and ${\sigma}_{Y}$ and the mean values $\overline{DT},\overline{DX},\mathrm{and}\overline{DY}$ on the time and magnitude of the events. The red dots and bars are the population mean values and standard deviations, respectively.

**Figure 4.**(

**a**) Comparison of the metric distribution for YAK/NER pairs (blue histogram) and the same metric for YAK/YAK earthquakes (red histogram). (

**b**) Threshold optimization: the red line shows the probability of missing a duplicate in the model with metric (1), the blue line is the probability of a false duplicate (see text), the black line is the total probability of errors of the first and second kind, the dashed line Ro = 5.8 corresponds to an equal number of errors of the first and of the second kind (the number of false duplicates is equal to the number of missed duplicates), the estimate of the total number of errors is approximately 0.5%, and the gray bar shows the range of values for the metric Ro = 6.3 ÷ 7.9, minimizing the total number of errors (approximately 0.4%).

**Figure 5.**Distribution of normalized DT and DR and metric level lines (1). The colored dots are YAK/NER pairs and the black dots are the distances between YAK/YAK events in metric (1). The metric levels Ro = 5.8 and Ro = 7.9 are shown by black lines, and absolute duplicates are not shown.

**Figure 7.**Distributions of DT, DX, and DY for the nearest events from the RUS and ISC_Other catalogs, and the dependence of the standard deviations ${\sigma}_{T}$, ${\sigma}_{X}$, and ${\sigma}_{Y}$ and the mean values $\overline{DT},\overline{DX},and\overline{DY}$ on the time and magnitude of the events. The red dots and bars are the population mean values and standard deviations, respectively.

**Figure 8.**(

**a**) Comparison of the metric distribution for RUS/ISC_Other pairs (blue histogram) and the same metric for RUS/RUS earthquakes (red histogram). (

**b**) Threshold optimization: the red line is the probability of missing a duplicate in the model with metric (1), the blue line is the probability of a false duplicate, the black line is the total probability of errors of the first and second kind, the dashed line Ro = 6.0 corresponds to an equal number of errors of the first and second kind (number of false duplicates is equal to the number of missed duplicates), the estimate of the total number of errors is approximately 0.3%, and the gray bar shows the range of values for the metric Ro = 6.7 ÷ 7.6, minimizing the total number of errors (approximately 0.2%).

**Figure 9.**Distribution of normalized DT and DR, and metric level lines (1). The colored dots are the RUS/ISC_Other pairs and the black dots are the distances between the RUS/RUS events in metric (1). The metric levels Ro = 6 and Ro = 7.6 are shown by the black lines, and absolute duplicates are not shown.

**Figure 10.**Distributions of DT, DX, and DY for the nearest events from the CORE/RUS_ISC catalogs, and the dependence of the standard deviations ${\sigma}_{T}$, ${\sigma}_{X}$, and ${\sigma}_{Y}$ and the mean values $\overline{DT},\overline{DX},\mathrm{and}\overline{DY}$ on the time and magnitude of the events. The red dots and bars are the population mean values and standard deviations, respectively.

**Figure 11.**(

**a**) Comparison of the distribution of the metric for the CORE/RUS_ISC pairs (blue histogram) and the same metric for the CORE/CORE earthquakes (red histogram). (

**b**) Threshold optimization: the red line is the probability of missing a duplicate in the model with metric (1), the blue line is the probability of a false duplicate, the black line is the total probability of errors of the first and second kind, the dashed line Ro = 5.9 corresponds to an equal number of errors of the first and second kind (number of false duplicates is equal to the number of missed duplicates), the estimate of the total number of errors is approximately 0.4%, and the gray bar shows the range of values of the metric Ro = 6.5 ÷ 8.4, minimizing the total number of errors (approximately 0.3%).

**Figure 12.**Distribution of normalized DT and DR and metric level lines (1). The colored dots are the CORE/RUS_ISC pairs and the black dots are the distances between the CORE/CORE events in metric (1). The metric levels Ro = 5.9 and Ro = 8.4 are shown by lines.

**Figure 13.**Correlation ratios of GCMT and ISC magnitudes: (

**a**) M

_{W}

^{GCMT}and mb

^{ISC}for M

_{W}< 6.0 and (

**b**) M

_{W}

^{GCMT}and M

_{S}

^{ISC}for M

_{W}≥ 6.0. The dashed lines show 95% confidence intervals. The events with an M

_{W}of ≥6.0 are highlighted in red.

**Figure 14.**Correlation ratios of the energy classes K

_{PS}and K

_{S}and the magnitude mb

^{ISC}. (

**a**) Northeast, K

_{PS}; (

**b**) Yakutia, K

_{PS}; and (

**c**) Kamchatka, K

_{S}. The dashed lines show 95% confidence intervals.

**Figure 15.**(

**a**) NEIC; (

**b**) MOS; (

**c**) EIDC; and (

**d**) IDC. Correlations of the “shift” type are determined in the interval of the magnitudes indicated in Table 4. The dashed lines show 95% confidence intervals.

**Figure 16.**Correlation ratios “shift” of the magnitudes YARS and mb

^{ISC}. (

**a**) ML

^{YARS}. (

**b**) MSV

^{YARS}. The dashed lines show 95% confidence intervals.

**Figure 17.**Correlation ratios “shift” of (

**a**) the ML

^{AEIC}and mb

^{ISC}magnitudes; indirect relationships; (

**b**) ML

^{AEIC}and ML

^{NEIC}; and (

**c**) ML

^{AEIC}and mbLG

^{NEIC}. The dashed lines show 95% confidence intervals.

**Figure 18.**Correlation ratios of the magnitudes MSUGS, USCGS, and mb

^{ISC}. (

**a**). M

^{MSUGS}. (

**b**) mb

^{USCGS}. The dashed lines show 95% confidence intervals.

**Figure 19.**Poorly defined “shift” correlations with the magnitude mb

^{ISC}. (

**a**) M

^{LAO}; (

**b**) M

^{ZEMSU}; and (

**c**) M

^{MOS}. The dashed lines show 95% confidence intervals.

**Figure 20.**(

**a**) Distribution of the magnitude of events in time. (

**b**,

**c**) Magnitude–frequency graphs before 1982 (

**b**) and after 1982 (

**c**). Before 1982, the energy classes were integers, and so the magnitudes are in increments of 0.5.

**Figure 21.**Map of earthquake epicenters of the integrated catalog of the Eastern Sector of the Arctic zone of the Russian Federation. The red and blue circles are the epicenters from the catalogs of GS RAS and ISC, respectively.

Catalog | Period | Number of Earthquakes with Energy Classes and/or Magnitudes | Number of Earthquakes with Unknown Energy Classes and Magnitudes |
---|---|---|---|

YAK | 1962, 1968–2019 | 6600 | 46 |

NER | 1968–2019 | 7668 | 1 |

KAM | 1962–2019 | 4498 | 0 |

Agency Abbreviation | Agency | Number of Earthquakes with Energy Classes and/or Magnitudes * |
---|---|---|

AEIC | Alaska Earthquake Information Center, USA | 184 |

ANDRE | USSR | 16 |

ANF | USArray Array Network Facility, USA | 2 |

BJI | China Earthquake Networks Center, China | 1 |

BYKL | Baykal Regional Seismological Centre, GS SB RAS, Russia | 4 |

DNAG | USA | 13 |

EIDC | Experimental (GSETT3) International Data Center, USA | 22 |

GCMT | The Global CMT Project, USA | 1 |

IDC | International Data Centre, CTBTO, Austria | 123 |

ISC | International Seismological Centre, United Kingdom | 1507 |

KRSC | Kamchatka Branch of the Geophysical Survey of the RAS, Russia | 2684 |

MATSS | USSR | 1400 |

MOS | Geophysical Survey of Russian Academy of Sciences, Russia | 26 |

MSUGS | Michigan State University, Department of Geological Sciences, USA | 2585 |

NEIC | National Earthquake Information Center, USA | 192 |

NEIS | National Earthquake Information Service, USA | 1 |

NERS | North Eastern Regional Seismological Centre, GS RAS, Russia | 4688 |

NKSZ | USSR | 8 |

SBDV | USSR | 107 |

SYKES | Sykes Catalogue of earthquakes 1950 onwards | 2 |

USCGS | United States Coast and Geodetic Survey, NEIC, USA | 1 |

WASN | USA | 328 |

YARS | Yakutiya Regional Seismological Center, GS SB RAS, Russia | 2256 |

ZEMSU | USSR | 1884 |

Total: | 18,035 |

Stage | Main Catalog | Additional Catalog | $\mathbf{Metric}\text{}\mathbf{Parameters}\text{}{\mathit{\sigma}}_{\mathit{T}}$$\text{}\mathbf{min},\text{}{\mathit{\sigma}}_{\mathit{X}}$$\text{}\mathbf{km},\text{}\mathbf{and}\text{}{\mathit{\sigma}}_{\mathit{Y}}\text{}\mathbf{km}$ | Threshold Value of the Metric | Estimation of the Number of Errors | Number of Duplicates | Merged Catalog |
---|---|---|---|---|---|---|---|

1 | Catalog of Yakutia YAK 6600 events | Catalog of the Northeast of Russia NER 7668 events | 0.041; 17.4; 16.3 | 5.8 | 0.5% | 2153 | YAK_NER 12,115 events |

2 | YAK_NER 12,115 events | Earthquake catalog of the Kamchatka Branch of the GS RAS KAM 4498 events | 0.041; 17.4; 16.3 | 5.8 * | – | 26 * | RUS 16,587 events |

3 | RUS 16,587 events | ISC, events of various agencies ISC_Other 16,642 events | 0.032; 12.3; 12.0 | 6.0 | 0.3% | 10,231 | RUS_ISC 22,998 events |

4 | CORE 1383 events | RUS_ISC 22,998 events | 0.044; 18.3; 18.3 | 5.9 | 0.4% | 1011 | ARCTIC 23,370 events |

5 | Exclusion of explosions EXP 116 events | ARCTIC 23,370 events | 0.05; 15.0; 15.0 | – | 0% | 116 ** | E_ARCTIC 23,254 events |

Agency | Type of Magnitude | Priority | Number of Events | Formula for Magnitude in the Integrated Catalog | Figure | M_{min}–M_{max}. Initial Magnitude Scale | Note |
---|---|---|---|---|---|---|---|

GCMT | M_{W} | 1 | 105 | M = M_{W}^{GCMT} | 4.7–7.6 | ||

ISC | mb | 2 | 1287 | M = mb^{ISC} | Figure 13a | 3.0–5.9 | |

ISC | M_{S} | 1 | 4 | M = M_{S}^{ISC} | Figure 13b | 5.7–7.5 | Strong events before 1976 |

YAK, NER, agencies of Russia and the USSR from ISC | K_{PS} | 3 | 16,301 | M = 0.5 K_{PS} − 1.6 | Figure 14a,b | 0.6–14.0 | Information about energy classes is given in the ISC bulletins |

KAM, KRSC | K_{S} | 3 | 4050 | M = 0.5K_{S} − 0.75 | Figure 14c | 3.0–13.1 | |

NEIC, NEIS | mb | 4 | 27 | M = mb^{NEIC} − 0.2 | Figure 15a | 3.5–4.9 | |

MOS | mb | 4 | 16 | M = mb^{MOS} − 0.2 | Figure 15b | 4.0–4.8 | |

EIDC | mb | 4 | 24 | M = mb^{EIDC} + 0.2 | Figure 15c | 3.0–4.3 | |

IDC | mb | 4 | 107 | M = mb^{IDC} + 0.2 | Figure 15d | 2.9–4.4 | |

YARS | ML | 4 | 357 | M = ML^{YARS} + 0.6 | Figure 16a | 0.5–3.0 | Unreliable correlation |

YARS | MSV | 4 | 95 | M = MSV^{YARS} + 0.2 | Figure 16b | 0.0–2.1 | Unreliable correlation |

AEIC | ML | 4 | 351 | M = ML^{AEIC} | Figure 17a | 2.2–4.2 | |

MSUGS | M | 4 | 24 | M = M^{MSUGS} + 0.1 | Figure 18a | 0.1–4.6 | |

USCGS | mb | 4 | 1 | M = mb^{USCGS} | Figure 18b | 4.1 | Unreliable correlation |

YARS | M | 4 | 104 | M = M^{YARS} + 0.1 | 3.2–3.3 | Indirect correlation with energy class. The magnitude M^{YARS} represents a conversion from the energy class K_{S} according to the formula of Rautian M^{YARS} = (K_{S} − 4)/1.8.For M[3.2–3.3] up to rounding, this is a shift of 0.1. | |

NERS | M | 4 | 24 | M = M^{NERS} + 0.2 | 2.3–2.5 | Indirect correlation with energy class. The magnitude M^{NERS} represents a conversion from the energy class K_{PS} according to the formula of Rautian M^{NERS} = (K_{PS} − 4)/1.8.For M[2.3–2.5] up to rounding, this is a shift of 0.2. | |

NEIC | ML | 4 | 13 | M = ML^{NEIC} − 0.1 | Figure 17b | 2.5–4.2 | Unreliably used indirect correlation ML^{AEIC} |

NEIC | mbLg | 4 | 2 | M = mbLg^{NEIC} + 0.1 | Figure 17c | 2.6–3.0 | Unreliably used indirect correlation ML^{AEIC} |

LAO | M | 4 | 2 | M = M^{LAO} | Figure 19a | 4.0 | Very unreliable correlation |

ZEMSU | M | 4 | 2 | M = M^{ZEMSU} | Figure 19b | 3.4–4.5 | Very unreliable correlation |

MOS | M | 4 | 1 | M = M^{MOS} + 0.1 | Figure 19c | 5.0 | Very unreliable correlation |

NEIC | M | 4 | 6 | M = M^{NEIC} | 2.5–4.9 | Very unreliable correlation. Only three events with two magnitudes were found, M^{NEIC} = mb^{ISC}. | |

ANF | ML | 4 | 2 | M = ML^{ANF} − 1 | 4.2–4.3 | Very unreliable correlation. Found only two events with two magnitudes, ML^{ANF}>>mb^{ISC}. | |

DNAG | M | 4 | 14 | M = M^{DNAG} | 2.5–4.4 | Correlation not established | |

WASN | M | 4 | 328 | M = M^{WASN} | 0.1–4.4 | Correlation not established | |

ZEMSU | MPV | 4 | 1 | M = MPV^{ZEMSU} | 4.5 | Correlation not established | |

YARS | MU | 4 | 2 | M = MU_YARS | 1.7–2.1 | Correlation not established | |

OTT | ML | 4 | 1 | M = ML^{OTT} | 3.9 | Correlation not established | |

PAL | M | 4 | 1 | M = M^{PAL} | 4.7 | Correlation not established | |

BJI | mb | 4 | 1 | M = mb^{BJI} | 4.8 | Correlation not established | |

EIDC | ML | 4 | 1 | M = ML^{EIDC} | 2.8 | Correlation not established | |

Total | 23,254 |

Date | TIME | Lat | Lon | Dep | Mag | ||
---|---|---|---|---|---|---|---|

1 | 22.11.1969 | 23:09:38 | 57.67 | 163.51 | 25.6 | 7.5 | M_{S}^{ISC} |

2 | 18.05.1971 | 22:44:41 | 63.93 | 145.96 | 1.5 | 7.0 | M_{S}^{ISC} |

3 | 08.03.1991 | 11:36:31 | 60.83 | 167.08 | 16.5 | 6.6 | M_{W}^{GCMT} |

4 | 24.10.1996 | 19:31:55 | 66.92 | −173.04 | 22.2 | 6.0 | M_{W}^{GCMT} |

5 | 20.04.2006 | 23:25:02 | 60.88 | 167.05 | 23.9 | 7.6 | M_{W}^{GCMT} |

6 | 21.04.2006 | 4:32:44 | 60.45 | 165.96 | 14.6 | 6.1 | M_{W}^{GCMT} |

7 | 21.04.2006 | 11:14:16 | 61.30 | 167.75 | 22.8 | 6.0 | M_{W}^{GCMT} |

8 | 29.04.2006 | 16:58:06 | 60.45 | 167.62 | 10.9 | 6.6 | M_{W}^{GCMT} |

9 | 22.05.2006 | 11:11:59 | 60.73 | 165.81 | 13.9 | 6.6 | M_{W}^{GCMT} |

10 | 22.06.2008 | 23:56:30 | 67.70 | 141.39 | 18.8 | 6.1 | M_{W}^{GCMT} |

11 | 30.04.2010 | 23:11:43 | 60.46 | −177.91 | 14.7 | 6.5 | M_{W}^{GCMT} |

12 | 30.04.2010 | 23:16:29 | 60.48 | −177.60 | 18.3 | 6.3 | M_{W}^{GCMT} |

13 | 24.06.2012 | 3:15:01 | 57.50 | 163.41 | 16 | 6.0 | M_{W}^{GCMT} |

14 | 14.02.2013 | 13:13:52 | 67.52 | 142.70 | 8.9 | 6.7 | M_{W}^{GCMT} |

15 | 09.01.2020 | 8:38:08 | 62.36 | 171.06 | 10 | 6.4 | M_{W}^{GCMT} |

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Gvishiani, A.D.; Vorobieva, I.A.; Shebalin, P.N.; Dzeboev, B.A.; Dzeranov, B.V.; Skorkina, A.A.
Integrated Earthquake Catalog of the Eastern Sector of the Russian Arctic. *Appl. Sci.* **2022**, *12*, 5010.
https://doi.org/10.3390/app12105010

**AMA Style**

Gvishiani AD, Vorobieva IA, Shebalin PN, Dzeboev BA, Dzeranov BV, Skorkina AA.
Integrated Earthquake Catalog of the Eastern Sector of the Russian Arctic. *Applied Sciences*. 2022; 12(10):5010.
https://doi.org/10.3390/app12105010

**Chicago/Turabian Style**

Gvishiani, Alexei D., Inessa A. Vorobieva, Peter N. Shebalin, Boris A. Dzeboev, Boris V. Dzeranov, and Anna A. Skorkina.
2022. "Integrated Earthquake Catalog of the Eastern Sector of the Russian Arctic" *Applied Sciences* 12, no. 10: 5010.
https://doi.org/10.3390/app12105010